Justine Bieber Posts shirtless selfies on Instagram during hiking trip in Los Angeles. To combat air pollution, he wore medical mask over his mouth. Justine Bieber captioned took Instagram to share these shirtless pics with his fans and captioned- “Air Quality in la,” “good thing I wore my mark!!”. 22-year-old singer raise the voice against the quality of air in Los Angeles. Let check it out and don’t forget to share with your friends.